The age of dinosaurs ended in cataclysm one spring day 66 million years ago when an asteroid 7.5 miles (12 kilometers) wide hit Mexico s Yucatan peninsula, triggering the extinction of those remarkable beasts and about three quarters of Earth s species.
WASHINGTON The age of dinosaurs ended in cataclysm one spring day 66 million years ago when an asteroid 7.5 miles (12 km) wide hit Mexico's Yucatan peninsula, triggering the extinction of those remarkable beasts and about three quarters of Earth's species. But were the dinosaurs already on the way out, with diversification faltering and rates of evolution sputtering, as.
By Will Dunham WASHINGTON (Reuters) - The age of dinosaurs ended in cataclysm one spring day 66 million years ago when an asteroid 7.5 miles (12 km) w.